javascript - Retrieve value from input next to a button using THIS selector -

i ran problem, have 2 siblings, input , button calls function retrieve value in input, keeps telling me value undefined...

here's "form":

<li>  <input id="mem3" value="testu4" disabled="">  <button id="del3" class="delmem" onclick="deletebandmember();">remove</button>  </li>

here's jquery code:

function deletebandmember() {    var mmbr = $(this).prev("input").val();  //<-returns undefined  }

i need use selector there many dynamically-created inputs... thanks!

pass this parameter in deletebandmember function shown :-

html :-

<li> <input id="mem3" value="testu4" disabled=""> <button id="del3" class="delmem" onclick="deletebandmember(this);">remove</button> </li>

jquery :-

function deletebandmember(elem){    var mmbr = $(elem).prev("input").val(); }

Script